Advanced Micro Devices Corporation

Cisco Technology, Inc.

Peter Chow

Jenny Liu Fischer

Harand Gaspar

Robert Alan Williams

Bahadir Erimli

Ching Yu

Kishore Karighattam

Gopal S Krishna

Robert Pryor Beliles, Jr

Massimo Civilini

Whu-ming William Young

Glenn Dasmalchi

A method and system for protecting a packet switched network from compromised communications due to a physical intrusion in the network are disclosed. The network includes at least one network element having a detection device operable to detect a possible physical intrusion in a data communication path connected to the network element. The method includes receiving a notification from the detection device that the detection device has identified a physical intrusion in the data communication path, generating an alert, and transmitting the alert over the packet switched network. The alert may include instructions on how to remediate the physical intrusion that can be automatically implemented by a given network-connected device or manually addressed by a network user or network administrator.

Method and system for protecting communication networks from physically compromised communications

Aspects for performing localized diagnostics in a station of a home phoneline networking alliance (HPNA) network are described. The aspects include providing a network state and control register comprising a plurality of bits to indicate status of a network state machine of an HPNA media access controller (MAC). A test mode bit is also provided as one of the plurality of bits in the network state and control register. The test mode bit allows overriding of one or more other bits in the network state and control register to direct changes to the network state machine logic state and diagnose performance in response to the changes.

Network state diagnostics for a home phoneline networking alliance media access controller (HPNA MAC)

The present invention provides a method for supporting frame priority in a home phone line network. The method includes: detecting a limited automatic repeat request (LARQ) header in a frame with a priority tag; stripping the LARQ header and a frame check sequence (FCS) in the frame with the priority tag; recalculating the FCS for the stripped frame with the priority tag; and adding the recalculated FCS to the stripped frame with the priority tag. The method strips the LARQ header from a HPNA frame with the priority tag before it is sent to an Ethernet controller. By stripping the LARQ header, the Ethernet controller will correctly recognize the priority tag and send the frame to the appropriate priority queue. In this manner, frame priority is supported.

Mechanism to strip LARQ header and preserve LARQ header in status frame

A method for communicating a Physical Layer (PHY) mean square error (MSE) to an upper layer device driver includes: receiving a frame by the PHY; computing a MSE for the frame by the PHY; sending the MSE and the frame to a Media Access Control (MAC); inserting the MSE into a frame status frame (FSF) associated with the frame by the MAC; and sending the frame and the FSF to the upper layer driver software. With access to the PHY MSE, the upper layer driver software can compute the average mean square error (AMSE) and determine if a change in the payload encoding (PE), or data transmission rate, should be negotiated. In this manner, the data transmission rate can be optimized while maintaining a low error rate.

Method to communicate PHY mean square error to upper layer device driver for rate negotiation

A method and system for maintaining synchronization in a home network is disclosed. The home network includes a host ethernet media access controller and an HPNA chip, where control frame and data frame pairs are transferred between the host ethernet media access controller (MAC) and the HPNA chip. The method and system include sending a null frame from the host ethernet MAC to the HPNA chip prior to the data frame, and recognizing the null frame on the HPNA chip as an indication that a next received frame will be the data frame, thereby maintaining synchronization between the control frame and the data frame pairs.

Maintaining synchronization between frame control word and data frame pairs in a home network

Aspects for collision recovery interface support in a home phoneline networking alliance (HPNA) control chip are described. The aspects include providing transmit data path logic to receive and transmit data packets within the HPNA control chip. The transmit data path logic is consolidated to include a transmit state machine that handles interfacing the transmit data path logic to at least two separate collision recovery logic means of the HPNA control chip through a minimal number of generic interface signals.

Collision recovery interface support in a home phoneline networking alliance media access controller (HPNA MAC) operating in accordance with at least two different data rate standards

A method and system for deferring transmission of a data packet over a home network is disclosed, where the home network includes a host media access controller program and a media access controller. The method and system include transmitting a first transmit signal from the host media access controller program to the media access controller (MAC) to transmit a data packet, and asserting a transmit start signal from the MAC in response. The method and system further include receiving a carrier sense signal on the MAC indicating activity on a transmission medium, and delaying assertion of a final transmit signal when it is determined that both the transmit start signal and the carrier sense signal are active, thereby avoiding packet collisions.

Home network transmission deferral

A method and system for verifying collision detection and resolution in a home network that comprises a plurality of stations is disclosed. Each station in the network includes a host media access controller program and a media access controller, where each station may transmit a frame when a transmission channel is inactive. When a collision is detected, the station ceases transmission of the frame, and chooses a backoff level to resolve the conflict. The station increments a backoff level counter in response to receiving backoff signal from another station on the network, and decrements the backoff counter in response to successfully transmitting the frame. The backoff level counter is maintained such that it may be accessed through the host media access controller for monitoring collision resolution, thereby eliminating the need to monitor signals over the network.

Verification of collision detection and resolution in a home network

A method and system for performing a two-step read on a count register as an atomic read in a home network is disclosed. The count register has a lower half and an upper half, and is incremented in response to an increment signal and is read in response to a read signal. The method and system include reading the lower half of the count register and storing the upper half of the count register in a shadow register in response to detecting the increment signal. The shadow register is then read in order to obtain the value of the upper half of the count register, thereby avoiding reading an incorrect result from the register.

Performing a two-step read on a MAC register in a home network as an atomic read

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter within any one of the respective switch ports if backpressure is asserted by that port. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of winning collision mediation under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch.

Apparatus and method for resetting a retry counter in a network switch port in response to exerting backpressure

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter for counting data packet transmission attempts within any one of the respective switch ports if backpressure is asserted by that port. A retry limit value for the retry counter is selectively modified according to programmed information to ensure that the total number of retrys does not exceed a maximum total number of allowable retrys. Resetting the retry counter within a port after assertion of backpressure affords the port a greater probability of transmitting earlier under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch. Selective modification of the retry limit value according to programmed information adds flexibility to vary the maximum total number of allowable retrys based upon current network switch conditions or the priority of a particular data packet.

Apparatus and method for programmably modifying a limit of a retry counter in a network switch port in response to exerting backpressure

A network switch having switch ports for communication of data packets with respective computer network nodes according to CSMA/CD protocol that resets a retry counter for counting data packet transmission attempts within any one of the respective switch ports if backpressure is asserted by that port. A retry limit value for the retry counter is modified to ensure that the total number of retrys does not exceed a maximum total number of allowable retrys. The resetting of the retry counter within a port after assertion of backpressure affords the port a greater probability of transmitting earlier under the CSMA/CD protocol, thus more quickly relieving congestion which may occur in the network switch. The modification of the retry limit value ensures that the number of retrys for the port does not exceed industry standards.

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San Jose, CA, United States of America

Peter Chow